This is a dual 18650 box mod, with a magazine style clip to insert your batteries with improved battery contacts and color styles. To access the battery magazine, simply push up on the magazine, slide the clip, and pull down. The Arms Race V2 Limitless Box Mod has a rugged design that is sturdy, yet affordable. This comes with a new custom chip that can fire down to .1 ohms, that is very user friendly, and simple to navigate. The top of the Arms Race V2 Limitless Box Mod fits most 25mm atomizers, with a built in side airflow access port.